Carburetor



Dec. 30, 1930.

E. G. ATKINS 1,787,230

CARBURETOR Filed Oct. 24. 1927 2 Sheets-Sheet l IzwenTor 6/ Q Eduard G. Atkins Dec. 30, 1930;

E. G. ATKINS 1,787,230

CARBURETOR I Filed Oct. 24, 1927 2 Sheets-Sheet 2 IIIIIIIIIIJ'II'II/ ATTor n zg meme so, 1930 mm STATES PATENT GFFICE EDWARD G. ATKINS, O]? JACKSON, MICHIGAN, ASSIGNOR TO WOLVEBINE CABBUBETOB comm, F JACKSON, MICHIGAN, A CORPORATION OF MICHIGAN CARBUBETOR Application filed October 24.19. Serial No. 228,152.

This invention relates to a carburetor designed for application to an internal combustion engine. It is an object and purpose of the present invention to provide a carburetor in which the proper proportions of air and. fuel are maintained automaticallyunder all of the running conditions which an engine has to undergo when used in an automobile, it being apparent that there are continual changes in level where an automobile is going up and down grades, that there are jolts and vibrations and many other severe conditioiis which do not have to be taken into account with carburetors for stationary engines. And, the carburetor which I have designed has as one of its primary objects and purposes the proper automatic maintenance of the right proportion of air and fuel under all of these conditions and throughout the many different speeds of the engine to which the carburetor is attached. It is a further object and purpose of the invention to provide a carburetor in which the fuel is automatically drawn through the carburetor from the main tank therefor without regard to the location of the tank. whether it is above or below the carburetor and this without the necessity of usinga vacuum tank. pump or similar means such as are now in common use.

A still further object of my invention is to provide a. carburetor capable of obtaining the results stated. yet which is comparatively simple in its structure and in the parts used and which is not liable to get out of order when in service.

A still further object of the invention is to provide a carburetor having a passage through which fuel may be drawn to deliver the same to a mixing chamber in the carburetor, and to so design and construct said passage as to eliminate the possibility of air pockets "therein. The passage at. certain points has various enlargements necessitated for the reception of certain operative mecha nisms of the carburetor, and the outlet of every enlargement in the passage is from a high point of the enlargement so that the carburetor. when located in either of the two positions that it is applied to an engine as commonly used, empties from the high point of every enlargement in the passage with a total elimination of any possibility of air pockets forming in said passage for'fuel.

A still further object of the invention is to provide a carburetor wherein the drop below atmospheric pressure in the mixing chamber will be higher than is customary at low speeds of the engine and will be lower than customary at high speeds. This is made possible by'the design which permits the use of an exceptionally long coiled compression spring which iscompressed when the air valve is opened and is of a tension such that the air valve will not openat low speeds as easily as in ordinary carburetors, but when opened, the tension of the spring is not greatly increased because of its extra long length, so

that there is not a marked decrease in the pressure below atmospheric pressure in the mixing chamber and as high a vacuum at high speeds of the engine as has heretofore been customary.

These and many other objects and purposes, not atthis time specifically stated, will appear fully as understanding of the invention is had from the following description taken in connection with the accompanying drawings illustrating the structure embodying my invention, in which drawings Fig. 1 is a side elevation of the carburetor of my invention.

Fig. 2 is a vertical section taken subtantially on the plane of line 22 of Fig. 3.

Figs. 3 and 4 are transverse sections taken substantially on the planes of lines 33 and H, respectively, of Fig. 2.

Fig. 5 is a perspective view illustrating a' detail of the structure used in operating and adjusting the degree of operation of the needle valve.

Fig. 6 is a fragmentary vertical section illustrating the choke mechanism of the carburetor which may be used to obtain a. richer fuel mixture in starting the engine when cold, and

Fig. 7 is a fragmentary transverse section substantially on the plane of line 77 of Fig. 2.

Like reference characters refer to like parts in the difierent figures of the drawings. In the construction of the carburetor an intermediate hollow body 1 is provided to which an air intake coupling 2 is secured,

formed with an inwardly facing valve seat. 3 against which a valve 4 normally seats.

A member 5 having a passage 6 therethrough is connected-at the oppositeside of the body 1, this member being adapted to be secured to the engine manifold. In the passage 6 a throttle valve 7 is mounted on a stem 8 which, at one end, carries an arm 9 through which the throttle valve is operated by the usual suitable operating means. -The two members 1 and 5 within the same and. below the throttle 7 provide a mixingchamber 10 where the fuel and air are-mixed before the same pass to the en 'n'e'manifold. V

Integral with the ody memberl is a sleeve 11 having a closed outer end, which sleeve extends upwardly and inwardly into thecham-. ber 10 as indicated at 12. A second sleeve 13 has a closed end which is permanently secured to the valve 4. Sleeve 13 is telescopically' received within the .sleeve 12 and between the closed ends of the two telescoping sleeves a coiled compression spring 14 is located being completely housed and acting normally to press the valve 4 against the seat 3.

largement 17 in such a way as to cut through the wall of the sleevell.

On the under side of the body member 1 is another member indicated as a whole at 19 and formed, at what may betermed its forward portion, with a disk-like part 20 to receive a flexible diaphragm 21 which is clamped between the part 20 and an overhanging somewhat concaved disk 22 cast integral with the body member 1. The diaphragm is securely clamped in place and below it an air-tight enlarged passage 24 is made, while the space above the diaphragm 21 has communication with the outside atmosphere through the vent opening 23.

- At one side of and slightly below the passage 24 is a part 25 bored longitudinally to provide a passage 26, the outer end of which is closed by a screw 26a. An 0 ening 27 is made between the passage 24 an ,the passage 26.

Projecting downwardly from themember 19 directly underneath the passage 24 IS a sleeve 28 interiorly bored to make a chamber 29 and interiorly threaded from lower end for a distance upward. The chamber 29 communicates with the passa e 24 b means of an opening 30 between t em. e sleeve 28 is surrounded by a screen 31 and openings32 are made through the sleeve 28 near the upper end thereof which communicate with the chamber 29. I 4

A plug 33 is screwed into the lower end of the sleeve 28 and has an opening; therethrough serving as a guide passage for the lower end of a valve stem 34 which, adjacent its upper end, is provided with a conical valve 36 to partly enter and close the opening 30 previously described. Normally the valve is moved upwardly by a coiled spring 35 located between it and the plug 33. The tension of the spring is adjusted by adjusting the plug 33 as is evident. The stem 34 above the valve. 36 extends into the passage 24 and at its upper end is equipped with a flat disklike head 37 lying against the underside of the diaphragm 21 at the central portion thereof.

A cup shaped housing 38 is located over and around the sleeve 29 and is permanently 29, and under suitable conditions, later to be described, which will cause the downward movement of the diaphragm 21 with a consequent downward movement of the valve 36, the opening 30 is opened to permit the passage of fuel to the passage 24 from which it may pass through the opening 27 into the passage 26.

The rear portion of the member 19 is formed to close the lower end of the passage enlargement 17, being formed into a cup shaped housing 42 open (at its upper side. A needle valve rod 43 extends into the rear end of the passage 26, the needle point 44 thereof entering a restriction in said passage, as best shown in Figs. 2 and 4. The needle valve is normally pressed by the spring 45 so as to move the point 44 in a direction to close the restricted portion of the passage. The spring 45 is located between a nut 46 secured thereto by a locking screw 39 threadthreaded through the rear side of the part 42 a stud 50 threaded thro lower rear end of the rod 16 previously described. The lower end of .lever 48 is divided to make two spaced apart depending legs 48a which set in slots in opposite sides of a bracket 49 supported at the upper end of ugh the lower side of the part- 42 of the member 19, stud 50 having a groove around it near its upper end and the bracket 49 having a slot 51 which receives the grooved ortion of the stud 50 (see Fig. 5). The brac 'et 49 also at its rear edge has an upturned finger 52 vertically slotted or divided between its edges, and a second screw threaded stud 53 engages with the finger 52 in the same way that the stud 50 engages with the bracket, the stud 53 being threaded through the rear side of the part 42. It is evident that, by adjusting the screw studs 50 and 53 the proper positioning of the needle valve may be accomplished. It will be noted that the axis of the stud 50 is parallel to the length of the lever 48 and that the axis of the stud 53 is perpendicular to the length of said lever.

from which it is turned. This permits independent adjustment of either of the studs without in any manner disturbing or altering the adjustment of the other. It is also evident that when, due to the suction of the engine, the valve 4 is moved inwardly there by moving the rod 16 longitudinally, lever 48 will be turned about its point of engagement with the bracket 49 and in this manner move the needle valve to partly open the restricted portion of the passage 26. It is also evident that by adjusting the screw stud 50 up and down the extent of movement of the needle valve with respect to the movement of the valve 4 may be controlled, as the fulcrum about which the lever 48 turns is changed by a vertical adjustment of the screyv 50.

Depending from the member 19 at one side of the passage 26 is a sleeve 54' the interior oiwhich communicates with the passage 24 through an opening 55 between them as shown in Fi 6. The lower end of the sleeve 54 is tlghtly closed by a nut 57 recessed at its lower side so that a continuous annular rib 57a is made around-the lower end of the nut. A valve stem 58 passes throughthe nut and into the sleeve 54 and at its upper end carries a conical valve 59 which normally projects into the opening 55 to close the same, being forced in an upward direction by a spring 60. The passage 56 connects the chamber 17 with the interior of the sleeve 54 and a similar passage 56a (Fig. 4)

connects-the interior chamber of the sleeve 54 with the passage 26 back of where the needle point 44 is located, as shown in Fig.

4. A nut 58a is threaded on to the lower end of the valve stem58 above which the stem 58 passes through a lever 61 bearin'g'against the Also that the up turned finger 52 is parallel to the lever 48 and. is perpendicular to the base of the lever 49 lower end of the nut 57 and sea at its end in the recess in said nut within e rib 57a.

A short tongue 62 is struck upwardly from the lever 61 and lies in the recess at the lower .illustrated in Fig. 2. When the carburetor is applied to an engine and whenthe suction or degree of vacuum in the mixing chamber 10 is such that spring 14 is compressed and the valve 4 opened, it is evident that a vacuum is produced in the chamber 24 and the pressure of air on the upper side of the diaphragm 21 will cause valve 36 to be moved downwardly opening the opening 30, whereupon .fuel willbedrawn through the pipe 40 and the various intervening connections into said passage enlargement 24, thence Pass into the passage 26 and to the point 44 o t needle valve. The opening of the air valve 4 moves the rod 16 longitudinally, operates the lever 48 and thus moves the needle valve back so as to partly open the restricted portion of the passage 26, whereupon the fuel is carried through the passages 56a and 56 to "the enlarged passage 17, thence through the passage 18 into the mixin chamber 10 to mix with the air coming into the chamber through an air inlet 2 and past the valve 4. The movement of the needle valve corresponds to the opening movement of the air valve 4. The tension of the spring 35 is adjusted so that all flow of fuel is cut off until the pressure drops or the degree of vacuum between the valves 36 and the needle point. 44 is suflicient to raise a column of fuel equal to the maximum lift any time required in the operation of the engine.

The tension of the spring 13 is such as to keep the valve 4 seated until a degree of Milk um within the mixing chamber 10-is quired for raising the fuel under any conditions of operation. The spring 13 is longer than is customarily used to hold an air inlet valve closed and its tension, when the air inlet is closed, is greater than the customary tension of springs for such purpose. Accordingly, the air valve will not open at low speeds of the engine until the pressure drop within the mixing chamber is greater than is customary in carburetors commonly used, insuring a degree of vacuum within the mixing chamber suflicient that the required amount of fuel will be raised under any conditions of engine operation. The length of P :1 duced equal to or greater than that re the spring further insures that its tension will not be greatly increased when the air valve is opened, inasmuch as its decrease in length will be only a small proportion or fraction of its total length. If the spring 13 was a short spring and its initial tension" was strong, gine when the airinlet valve was opened to a large extent would be very high, but on account of the design which permits the use of the long spring the tension is not greatly increased so that the degree of vacuum within the mixing chamber at high speeds of the engine is less than what is customary with carburetors as now used. The. telescoping sleeve dash-pot construction used in mounting the spring and its angular" setting is also of value in controlling and dampening the spring action whereby the air inlet valve does not flutter and strike against its seat with consequent undesirable noise.

The fuel, therefore, is drawn throughthe pipe 40 as fast as permitted b the opening of the needle valve, which in urn, being actuated by the suction operated'air valve 4, the fuel and air are admitted in roper proportions, the ta er of the need e valve 44' and the fuel a ission valve 36 are combined in an operative manner to insure that I the fuel and air in proper proportions will be delivered to the en 'ne by the carburetor and that the fuel will properly carried to the air irrespective of the level of the main fuel supply with respect to the level of the carburetor. It makes no difference whether the fuel level in the supply tank is above or.

below or in the same plane with the carburetor mixing chamber or the needle valve thereof and it is a matter .of no consequence how an automobile, having an'en ne equipped with this carburetor is incline to the horizontal,

whether it is goin up or down grade and what the percent of the grade is.

There is produced a proper proportioning of the air and fuel during the variations of the s ed of the engine and irrespective of the different amounts of mixed air and fuel required to drive the engine at its-various speeds. It eliminates all vacuum tanks, fuel pum s or other auxiliar means required for the elivery of fuel an the oper'ation'is in no wise affected by variation of fuel level in the supply tank. The construction is also fully satisfactory for use where the fuel is fed to the carburetor by gravity. In factthe carburetor is one of universal application.

The mechanism for adjusting the carbure-= tor for rich or lean mixtures is shown in Fig. 5. The degree that the needle valve is opened in proportion to the opening of the air inlet? valve 4 is. governed by the position of 'the' bracket 49 with respect to the ends of the legs 48a of lever 48. This maybe readily adjusted ,An extra supply of fuel for starting the for rich or lean mixtures.

itstension at high speeds of the en-.

engine when cold is available through the mechanism shown in Fig. 6 wherein by openmg the valve 59 on pulling on the wire 63 fuel may pass from the passa 24 ingreater amounts than it can pass by t e needle point I 44 with a resultant richness of mixture. The passage remains filled up to the point 18 at all times after the carburetor has been in use.

While the position of the carburetor no'rmally is that shown in Fi 1 that is with the outlet at 6 vertical the car uretor may be 10- tion. Many variations in the speci c detail of the structure may be resorted to without in 7 any way departing from the invention. The invention is defined in the claims appended hereto and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1 In a carburet0r,' the combination of a mixing chamber havmg'an air inlet and an outlet thereto, a spring pressed valve normally closing the air inlet and actuatedto open the air inlet by the excessof atmos pheric pressure over the pressure within said mixing chamber, a fuel conduit adapted to lead from a source of fuel supply to said mixmg chamber, two fuel valves in said fuel conduit, the first being located ne'aresttothemixmg chamber and the second-nearest to the source of fuel supply, interposed means between the air valve and the first of. said fuel valves for moving said first fuel valve when the air valve is opened to thereby withdraw a diaphragm bearing against the second fuel valve and flexing under atmospheric pressure when the pressure within said fuel conduit between the fuel valves has decreased sufli-- cient that the excess of atmospheric pressure acting on said diaphragm will overcome the spring, whereupon the second fuel valve is III] moved to open thei'fuel conduit, said spring suc acting on the second fuel valve being'o strength that; before ,thefuel conduit is" opened by movement of the second fuel valve a difference in. pressureis made between atmospheric pressure and' that; within the fuel conduit between @the fuel valve suflicient to raise a columnofliquid fuel equal to the maximam lift ever required in operation.

a. ,Ina carbufetoflthe combination of a mixing chamber having an air inlet normally closed by a spring actuated valve and opened by suction of an en ine to which the carburetor is adapted to v e attached, said carburetor having a dischar e outlet through which mixed air and fue may pass to said engine, a fuel feed passage including a diaphragm chamber covered by a diaphragm exposed to atmospheric pressure, a needle fuel feed valve projecting into said feed passage, means disposed between the air valve andfsaid needle fuel feed valve for actuating the-needle valve to open the fuel feed passage in proportion to the movement of the air valve, a second fuel valve located in said fuel feed passage, means interposed between the second valve and the diaphragm for moving said valve to open the passage on flexing the diaphragm under the influence of atmospheric pressure, and yielding means normally holding the second fuel valve in closed position, said yielding means being overcome by atmospheric pressure on the diaphragm when the second valve is opened.

3. In a carburetor, the combination of a mixing chamber having an air inlet normally closed by a spring actuated valve, and having a dlscharge outlet, a fuel feed passage adapted to lead from a source of fuel supp y to said mixingchamber closed at one side by a flexible dia hragm exposed at its outer side to atmospheric pressure, two fuel valves in said fuel feed passage at spaced apart points, the first being located nearest the mixing. chamber and the second nearer the source of fuel supply, means for automatically moving the first valve interposed between it and the air inlet valve when said air inlet valve isopened and in proportion to the amount that said air inlet valve is opened, yielding means normally holding the second fuel valve in v position to close .the fuel inlet passa e, a

stem having a head extending from sai second valve, said head contacting against the;

5 inner side of said diaphragm for the pur- POSGS dBSCIibGd'.

4. In a carburetor, the combination of a mixing chamber having an air inlet opening a and an outlet 0 ning, a spring actuated valve normally c osing said air inlet a mg, a fuel conduit for conducting fuel om' a source of supply to said mixing chamber, a needle fuel valve projecting into said fuel 7 passage to control the amount of fuel that passes to the mixing chamber, a pivotallv mounted lever :connected with the needle valve, a rod bearing against-the air inlet valve at one end and against the lever at located in said fuel conduit closing the same, yielding means holding the second valve in closed position, and means operated by atmospheric pressure'for moving said second valve to open position when said atmospheric pressure exceeds the pressure within said fuel v passage by an amount sufficient to overcome said yielding means.

In a carburetor, the combination of a mixing chamber having an air inlet closed by a spring actuated valve and an outlet provided with a throttle, an air tight fuel passage to said chamber, two fuel valves arranged in series in said fuel passage the first nearer to the mixing chamber than the second, means for actuatin said fuel valve nearest the mixing chamber y movement of said air valve when the same is open, means whereby the second ofsaid fuel valves is antomatically opened on drop of pressure in the fuel passage between said two valves caused by drop of pressure in the mixing chamber, and means for externally adjusting the first of said valves in the fuel passage to set the valve in said passage whereby in its normal position the passage will be partially opened and the extent to which it is open gov.- erned by said external adjustment therefor.

6. In a carburetor, the combination of a mixing chamber having an air inlet closed by a spring actuated valve, and a mixture outletwhereby the position of the lever is controlled by the spring actuated air valve.

In testimony whereof I afiix my signature.

I EDWARD G. ATKINS.

its other end moved by saidair inlet valve Y 90 when the same is opened to automatically and simultaneously withdraw the needle valve to permit the passage of fuel, said fuel passmg being in proportion to the air passed by the inlet valve irrespective of the extent that. 65 the 8.11 inlet valve is opened, a second valve 

